In many manufacturing operations, bar stock is processed to produce final piece parts; for example, bar stock may be fed automatically to shearing and heading machines to produce piece parts for springs. In this handling of the bar stock it is common practice to use a bar feeder which accepts the bar stock, one piece at a time, from a feed ramp. In supplying the feed ramp there has been a problem of automatically separating the bars from a bundle in a proper orientation to load the feed ramp. This, of course, has been done manually but a manual operation is unsatisfactory for several reasons. It has also been proposed in the prior art to automatically unscramble a bundle of bars, i.e., uniformly orient the bars in a bundle, and to feed them at a regulated rate to a transfer mechanism.
While the prior art discloses several different forms of bar unscrambling and feeding apparatus, this invention pertains to that type which is aptly described as the oscillating sling unscrambler and feeder. The oscillating sling apparatus comprises two or more slings, suitably chain slings, which form festoons and are adapted to receive a bundle of unoriented bars. The rear end of each sling is supported at a higher position than the front end and reversible drive means connected with the slings alternately shorten and lengthen the respective festoons and thereby raise and lower the bundle to orient the bars and to feed the bars, one at a time, out the front of the slings to a bar transfer means, such as a feeder ramp. Such an oscillating sling sling type unscrambling and feeding apparatus is disclosed in French Pat. no. 1,348,597 granted Dec. 2, 1963. Such an apparatus is also disclosed in the U.S. Pat. no. 3,506,142 granted Apr. 14, 1970. In the apparatus of both of the aforementioned patents the rear end of each sling is fixed and the festoon is shortened or lengthened by moving the forward end of the sling over a supporting pulley or sprocket wheel and this sling motion produces an unscrambling and feeding action of the bars.